Article ID Journal Published Year Pages File Type
206313 Fuel 2012 6 Pages PDF
Abstract

Self-cementitious properties of fly ash from circulating fluidized bed combustion boiler (CFBC) with limestone addition were investigated, especially the effect of lime on self-cementing process. The CFBC fly ash is self-cementitious and its main hydration products are ettringite (AFt), hydrated calcium silicate (CSH), portlandite, and gypsum. Slaking of free lime has a great effect on the self-cementing process of CFBC fly ash, accelerating the setting process. The self-cementing process of CFBC fly ash paste is based on three main reactions: (1) generation of Ca(OH)2 micelles by quick slaking of lime, (2) generation of AFt by active alumina reacting with CaSO4 and Ca(OH)2, and (3) generation of CSH by active silica reacting with Ca(OH)2.

► The CFBC fly ash is self-cementitious and its main hydration products are AFt, CSH, portlandite, and gypsum. ► Slaking of free lime accelerates the setting process of CFBC fly ash paste. ► The self-cementing process of CFBC fly ash paste is based on the generation of Ca(OH)2 micelle, AFt and CSH.

Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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